#!/bin/sh /etc/rc.common
# Copyright (C) 2007-2015 OpenWrt.org

START=70
STOP=01

USE_PROCD=1

KEEPALIVED_CONF=/tmp/keepalived.conf

INDENT_1=\\t
INDENT_2=$INDENT_1$INDENT_1

config_section_open() {
	local tag=$1
	local name=$2

	printf "$tag" >> $KEEPALIVED_CONF
	[ -n "$name" ] && printf " $name" >> $KEEPALIVED_CONF
	printf " {\n" >> $KEEPALIVED_CONF
}

config_section_close() {
	printf "}\n\n" >> $KEEPALIVED_CONF
}

config_foreach_wrapper() {
	local section=$1
	local function=$1

	# Convention is that 'function' and 'section' are the same
	config_foreach $function $section
}

print_elems_indent() {
	local config=$1
	shift
	local indent=$1
	shift
	[ -z "$indent" ] && indent="$INDENT_1"
	for opt in $*; do
		local $opt
		local no_val=0
		if [ ${opt:0:7} == "no_val_" ]; then
			opt=${opt:7}
			no_val=1
		fi
		config_get $opt $config $opt
		eval optval=\$$opt
		[ -z "$optval" ] && continue
		printf "$indent$opt" >> $KEEPALIVED_CONF
		[ "$no_val" == "0" ] && {
			local words=$(echo "$optval" | wc -w)
			if [ $words -gt 1 ]; then
				printf " \"$optval\"" >> $KEEPALIVED_CONF
			else
				printf " $optval" >> $KEEPALIVED_CONF
			fi
		}
		printf "\n" >> $KEEPALIVED_CONF
	done
	unset optval
}

print_list_indent() {
	local lst=$1
	local indent=$2
	local lst_elems
	[ -z "$indent" ] && indent=$INDENT_1

	eval lst_elems=\$$lst
	[ -z "$lst_elems" ] && return 0

	printf "$indent$lst {\n" >> $KEEPALIVED_CONF
	for e in $lst_elems; do
		[ -n "$eval_item_func" ]
		printf "$indent$INDENT_1$e\n" >> $KEEPALIVED_CONF
	done
	printf "$indent}\n" >> $KEEPALIVED_CONF
}

print_notify() {
	local type=$1
	shift
	local name=$1
	shift
	for notify in $*; do
		printf "$INDENT_1$notify" >> $KEEPALIVED_CONF
		notify=$(echo $notify | tr 'a-z' 'A-Z')
		printf " \"/bin/busybox env -i ACTION=$notify TYPE=$type NAME=$name /sbin/hotplug-call keepalived\"\n" >> $KEEPALIVED_CONF
	done
}

global_defs() {
	local linkbeat_use_polling notification_email

	config_get alt_config_file $1 alt_config_file
	[ -z "$alt_config_file" ] || return 0

	config_get_bool linkbeat_use_polling $1 linkbeat_use_polling 0
	[ $linkbeat_use_polling -gt 0 ] && printf "linkbeat_use_polling\n\n" >> $KEEPALIVED_CONF

	config_get notification_email $1 notification_email
	print_list_indent notification_email

	print_elems_indent $1 $INDENT_1 notification_email_from smtp_server smtp_connect_timeout \
	           router_id vrrp_mcast_group4 vrrp_mcast_group6
}

print_ipaddress_indent() {
	local section=$1
	local curr_ipaddr=$2
	local indent=$3

	local address device scope name
	config_get name    $section name
	[ "$name" != "$curr_ipaddr" ] && return 0

	config_get address $section address
	config_get device  $section device
	config_get scope   $section scope

	# Default indent
	[ -z "$indent" ] && indent=$INDENT_1

	# If no address or device exit
	[ -z "$address" -o -z "$device" ] && return 0

	# Add IP address/netmask and device
	printf "$indent$address dev $device" >> $KEEPALIVED_CONF
	# Add scope
	[ -n "$scope" ] && printf " scope $scope" >> $KEEPALIVED_CONF

	printf "\n" >> $KEEPALIVED_CONF
}

static_ipaddress() {
	local address
	config_get address "$1" address
	for a in $address; do
		config_foreach print_ipaddress_indent ipaddress $a
	done
}

print_route_indent() {
	local section=$1
	local curr_route=$2
	local indent=$3

	local name blackhole address src_addr gateway device scope table

	config_get name           $section name
	[ "$name" != "$curr_route" ] && return 0

	config_get_bool blackhole $section blackhole 0
	config_get address        $section address
	config_get src_addr       $section src_addr
	config_get gateway        $section gateway
	config_get device         $section device
	config_get table          $section table

	# If no address exit
	[ -z "$address" ] && return 0

	# Default indent
	[ -z "$indent" ] && indent=$INDENT_1

	[ $blackhole -gt 0 ] && {
		printf "${indent}blackhole $address\n" >> $KEEPALIVED_CONF
		return 0
	}
	# Add src addr or address
	if [ -n "$src_addr" ]; then
		printf "${indent}src $src_addr $address" >> $KEEPALIVED_CONF
	else
		[ -z "$device" ] && return 0
		printf "$indent$address" >> $KEEPALIVED_CONF
	fi
	# Add route/gateway
	[ -n "$gateway" ] && printf " via $gateway" >> $KEEPALIVED_CONF
	# Add device
	printf " dev $device" >> $KEEPALIVED_CONF
	# Add scope
	[ -n "$scope" ] && printf " scope $scope" >> $KEEPALIVED_CONF
	# Add table
	[ -n "$table" ] && printf " table $table" >> $KEEPALIVED_CONF
	printf "\n" >> $KEEPALIVED_CONF

}

print_track_elem_indent() {
	local section=$1
	local curr_track_elem=$2
	local indent=$3

	local script name value
	config_get name    $section name
	[ "$name" != "$curr_track_elem" ] && return 0

	config_get value  $section value
	config_get weight $section weight

	[ -z "$value" ] && return 0

	printf "$indent$value" >> $KEEPALIVED_CONF
	[ -n "$weight" ] && printf " weight $weight" >> $KEEPALIVED_CONF
	printf "\n" >> $KEEPALIVED_CONF
}

static_routes() {
	local route
	config_get route "$1" route
	for r in $route; do
		config_foreach print_route_indent route $r
	done
}

# Count 'vrrp_instance' with the given name ; called by vrrp_instance_check()
vrrp_instance_name_count() {
	local name
	config_get name $1 name
	[ "$name" == "$2" ] && count=$((count + 1))
}

# Check if there's a 'vrrp_instance' section with the given name
vrrp_instance_check() {
	local count=0
	local name=$1
	config_foreach vrrp_instance_name_count vrrp_instance $name
	[ $count -gt 0 ] && return 0 || return 1
}

vrrp_sync_group() {
	local group name
	local valid_group

	# No name for group, exit
	config_get name $1 name
	[ -z "$name" ] && return 0

	# No members for group, exit
	config_get group $1 group
	[ -z "$group" ] && return 0

	# Check if we have 'vrrp_instance's defined for 
	# each member and remove names with not vrrp_instance defined
	for m in $group; do
		vrrp_instance_check $m && valid_group="$valid_group $m"
	done
	[ -z "$valid_group" ] && return 0

	config_section_open "vrrp_sync_group" "$name"

	group="$valid_group"
	print_list_indent group

	print_elems_indent $1 $INDENT_1 no_val_smtp_alert no_val_global_tracking

	print_notify "GROUP" "$name" notify_backup notify_master \
		notify_fault notify

	config_section_close
}

vrrp_instance() {
	local name auth_type auth_pass

	config_get name $1 name
	[ -z "$name" ] && return 0

	config_section_open "vrrp_instance" "$name"

	config_get auth_type $1 auth_type
	config_get auth_pass $1 auth_pass
	[ -n "$auth_type" -a -n "$auth_pass" ] && {
		printf "${INDENT_1}authentication {\n" >> $KEEPALIVED_CONF
		printf "${INDENT_2}auth_type $auth_type\n" >> $KEEPALIVED_CONF
		printf "${INDENT_2}auth_pass $auth_pass\n" >> $KEEPALIVED_CONF
		printf "$INDENT_1}\n" >> $KEEPALIVED_CONF
	}

	print_elems_indent $1 $INDENT_1 use_vmac state interface \
		mcast_src_ip unicast_src_ip virtual_router_id version priority \
		advert_int preempt_delay debug \
		lvs_sync_daemon_interface garp_master_delay garp_master_refresh \
		garp_master_repeat garp_master_refresh_repeat \
		no_val_vmac_xmit_base no_val_native_ipv6 no_val_accept \
		no_val_dont_track_primary no_val_smtp_alert no_val_nopreempt

	print_notify "INSTANCE" "$name" notify_backup notify_master \
		notify_fault notify_stop notify

	# Handle virtual_ipaddress & virtual_ipaddress_excluded lists
	for opt in virtual_ipaddress virtual_ipaddress_excluded; do
		config_get $opt $1 $opt
		eval optval=\$$opt
		[ -z "$optval" ] && continue
		printf "$INDENT_1$opt {\n" >> $KEEPALIVED_CONF
		for a in $optval; do
			config_foreach print_ipaddress_indent ipaddress $a $INDENT_2
		done
		printf "$INDENT_1}\n" >> $KEEPALIVED_CONF
	done

	# Handle virtual_routes
	for opt in virtual_routes; do
		config_get $opt $1 $opt
		eval optval=\$$opt
		[ -z "$optval" ] && continue
		printf "$INDENT_1$opt {\n" >> $KEEPALIVED_CONF
		for r in $optval; do
			config_foreach print_route_indent route $r $INDENT_2
		done
		printf "$INDENT_1}\n" >> $KEEPALIVED_CONF
	done

	# Handle track_script lists
	for opt in track_script; do
		config_get $opt $1 $opt
		eval optval=\$$opt
		[ -z "$optval" ] && continue
		printf "$INDENT_1$opt {\n" >> $KEEPALIVED_CONF
		for t in $optval; do
			printf "$INDENT_2$optval\n" >> $KEEPALIVED_CONF
		done
		printf "$INDENT_1}\n" >> $KEEPALIVED_CONF
	done

	# Handle track_interface lists
	for opt in track_interface; do
		config_get $opt $1 $opt
		eval optval=\$$opt
		[ -z "$optval" ] && continue
		printf "$INDENT_1$opt {\n" >> $KEEPALIVED_CONF
		for t in $optval; do
			config_foreach print_track_elem_indent track_interface $t $INDENT_2
		done
		printf "$INDENT_1}\n" >> $KEEPALIVED_CONF
	done

	# Handle simple lists of strings (with no spaces in between)
	for opt in unicast_peer; do
		config_get $opt $1 $opt
		print_list_indent $opt
	done
	unset optval

	config_section_close
}

vrrp_script() {
	local name

	config_get name $1 name
	[ -z "$name" ] && return 0

	config_section_open "vrrp_script" "$name"

	print_elems_indent $1 $INDENT_1 script interval weight fall rise

	config_section_close
}

process_config() {
	local alt_config_file

	rm -f $KEEPALIVED_CONF

	# First line
	printf "! Configuration File for keepalived (autogenerated via init script)\n\n" > $KEEPALIVED_CONF

	[ -f /etc/config/keepalived ] || return 0
	config_load 'keepalived'

	config_section_open "global_defs"
	config_foreach_wrapper global_defs
	config_section_close

	# If "alt_config_file" specified, use that instead
	[ -n "$alt_config_file" ] && [ -f "$alt_config_file" ] && {
		rm -f $KEEPALIVED_CONF
		# Symlink "alt_config_file" since it's a bit easier and safer
		ln -s $alt_config_file $KEEPALIVED_CONF
		return 0
	}

	config_section_open "static_ipaddress"
	config_foreach_wrapper static_ipaddress
	config_section_close

	config_section_open "static_routes"
	config_foreach_wrapper static_routes
	config_section_close

	config_foreach_wrapper vrrp_script
	config_foreach_wrapper vrrp_sync_group
	config_foreach_wrapper vrrp_instance
	return 0
}

service_running() {
	pgrep -x /usr/sbin/keepalived &> /dev/null
}

conf_md5() {
	echo "$(md5sum $KEEPALIVED_CONF | awk '{print $1}')"
}

reload_service() {
	local cur_md5="$(conf_md5)"
	running && {
		process_config

		# Return without performing the reload if config
		# file md5sum has not changed
		local new_md5="$(conf_md5)"
		[ "$new_md5" == "$cur_md5" ] && return 0;

		# SIGHUP is used by keepalived to do init.d reload
		# Get the oldest process (assumption is that it's the parent process)
		PID=$(pgrep -o /usr/sbin/keepalived)
		kill -SIGHUP $PID
		return 0
	}
	return 1
}

start_service() {
	procd_open_instance
	procd_set_param command /usr/sbin/keepalived
	procd_append_param command -n # don't daemonize, procd will handle that for us
	procd_append_param command -f "$KEEPALIVED_CONF"

	process_config

	# set auto respawn behavior
	procd_set_param respawn
	procd_close_instance
}

